Club 80-90 Forums

Hi all

I have a 1.9DG, which today has developed a very loud knocking sound from the engine, which increases with revs. I haven't changed anything or done any work on it recently, except for replace the exhaust a couple of weeks ago.

Any ideas what it might be? Do I need to make another trip to Elite VW?

Exhaust silencer catching on the chassis ?

Ian.

Hi Ian

Thanks for the reply, but no I already checked that. It's definitely coming from the actual engine.

E D I T: I've just realised it started a few days ago, but I thought it was just the tappets doing that ... errr... tappetty thing.

I took a video of it. The sound is coming from the right hand side of the engine as you look at it from the rear.
http://www.youtube.com/watch?v=GHkgIx9akso" onclick="window.open(this.href);return false;

It sounds much more metallic than it came out on the vid.

Any ideas?

Er, does sound like a tappet - frequency of tap sounds like one. Get the right hand rocker off and have a nose. Could have just run dry of oil or something more challenging. Has engine been lowe on oil? Have you checked oil level?

Get a long screwdriver, put the handle hard against your earhole and put the end on the rocker case - you may even be able to tell which end it is before removing cover.

Before I took the vid, I changed the oil. I took the right hand side rocker cover off (cos it definitely sounds like it's coming from that area) and there was oil in there.

It hasn't been low on oil. It does burn oil, when first started oily smoke comes out of exhaust, and so I have to top up a small amount quite regularly, but it's never been below the low mark on dipstick.

I also checked the spark plugs and the one on right hand side furthest away (as you look from rear) was very black. I changed the plugs last time I serviced it about 6 months ago.

I ran a magnet through the old oil to see if there was anything metallic and I couldn't see anything.

One other thing. Before I changed the oil this morning, I ran the engine for only a minute or so (the noise was too freaking loud to run it any longer), but when I took the filler cap off, there was a small amount of smoke coming out.

Well I'd check the tappets along there. Make sure one of the adjusters hasn't come loose.

take it for a ten mile run, it will go.

Not always

jason k wrote:take it for a ten mile run, it will go.

Clearly the noise didn't come through on the video. It did start off as a tappety sound, but turned in to a much louder and more vicious noise a day later (after a 30 mile run).

Sounds a bit vicious for a tappet to me , and i think i would put in a bit excess of 20/50 oil ( cheap stuff in 1 litre from tesco) say 0.25 litre over dipstick mark ( thats about 3-4 mm ) and see if it goes away , my tappet noises always do and level is reduced over next few weeks .Careful, tho.
jaylo

have you took the rocker cover off and checked for a loose rocker?

get the piston on 1 and 2 to their respective firing positions (both valves shut) and push the rockers up and down.

I would guess it's a collapsed lifter.
relatively cheap from VW

Wot he said.

No loose rockers.

I've pinpointed the noise as coming from the area of number 1 cylinder. What could that be then?

Do a compression test next. Could be a little end but I've never had a little end go ever.